How Genetic Genealogy is Solving Cold Cases

The technique was not pioneered by the FBI or elite forensic experts but by a loose network of citizen scientists. The novel turn to crime-fighting has raised issues: Could the process finger the wrong person? Who will ensure police use genetic data responsibly?

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A young couple on a trip in 1987 crossed paths with a killer. The man raped Tanya Van Cuylenborg and shot her in the head. Jay Cook was beaten and strangled. The killer left a pair of plastic gloves inside their vehicle, a gesture one detective interpreted as a taunt: You’ll never catch me. That was true for more than three decades. Then in April, CeCe Moore, a former musical theater actor with no background in law enforcement, cracked the case in three days, the Washington Post reports. Moore, working at Virginia-based Parabon NanoLabs, put the killer’s DNA profile into a public genealogy website to find relatives and built a family tree that led to a suspect, William Earl Talbott II, who was charged in May.

Since the same technique was used to find the man accused of being the Golden State Killer, genetic genealogy has led to a flurry of breakthroughs in the coldest of cases, showing the potential to be a transformative tool for police. Parabon is the biggest player so far to work in the emerging field. Genetic genealogy was not pioneered by the FBI or elite forensic experts but by a loose network of citizen scientists. The novel turn to crime-fighting has raised issues: Could the technique finger the wrong person? Who will ensure police use genetic data responsibly? Should authorities rely on a public database that could be hacked or manipulated? The process uses GEDmatch, a genetic clearinghouse that allows users to find relatives by comparing their genetic code against more than 1 million others. GEDmatch’s analysis is a quantum leap over traditional DNA matching used by law enforcement since the 1980s. The profiles uploaded to GEDmatch containing 600,000 DNA snippets, allowing the genetic genealogist to determine how closely people are related.